Leuco body containing sulfur and process of making same.



To all whom it concern:

-loxisatin an alkyloxydioxindole UNI'ZT'ED STATES PATENT OFFICE.

zenuno I-IOMQLKA, on rnanxron'rson rnn- LEUCO BODY CONTAINING SULFUR No Drawing. 7 Application filed March 23,

Be it known that we, Bruno HoMoLKA, Ph. 1)., and ROBERT W'ELDE, Ph. ll, citizens of the Empire of Germany, residing .at Frankfort-on-the-Main and Hiichst-on-the Main, Germany, respectively, havefinvented certain new and useful Improvements in stufis Containing Sulfur, of which the following is a. specification.

According to A. Baeyer (see Berichae d6? 'Deutscizen Chemise/lien Gesellscizaft XII, 1309), by reducing isatin, the'dioxindole {emote-9o CH4. 6 'NH is obtained. In the same Way the substituted dioxindoles are obtained from the substituted isatins, for instance from an alkyoo-cwm CH(OH)CO All: 1 o o HS aVe have now found that the, dioxindoles combine with the alpha-oxyth1onaphthenes of the general formula:

forming leuco bodies of valuable sulfurized vat-dyestuffs. This combination is etl'ected by heating a dioxindole, dissolved or suspended in water, with an alpha-oxythionaphthene;. in presence of acids or alkali carbonates the reaction is accelerated. The alpha-oxythionaphthenes may also be used in the form of their beta-carboxylic acids; for instance instead of an alkyloxythionaphthene its carboxylicacid c ou Alkyl()C6II3 C COOH may be employed. In this case the carboxyl VAND PnooEss' or AK iTd SAME.

MAIN, AND ROBERT WELDE, or Hocns'r i ON-THE-MAIN, GERMANY, ASSIGNORS T0 FARBWERKE vo'mvr. M-EISTER LUCIUS &- BRI'TNING, OF HUCI-IST-ON-THE-MAIN, GERMANY, A ooRroRATmN QEGERMANYv;

Specification of Letters Patent. Patented Deb. 1909. I

1909. Serial No. 485,268.

gr.oup-C()OH is split oil and the simple or substituted alphaoxythionaphthene thus formed combines with the simple or substituted dioXindole which is present.

The following examples illustrate the invention:

Example I: A hot solution of 10 parts by weight of dioxindole in aboutlOOO parts of water, such as the solution which, for instance, is obtained according to Baeyer.(see-' Eerie/ate der Denise/ten O/zemz'schen GeseZZ- sc/mft XII, 1309) by reducing isatin with zinc and hydrocholio' acid, is mixed with 10 parts of alpha-oxythionaphthene or 15 parts of alpha-0Xythionaphthene-beta carboxylic acid, whereupon carbonate of soda is added until the mixture is alkaline. A mixture ofthe sulfurized leuco body thus formed with zinocarbonate then separates; this is collected on a filter and'the zinc carbonate is separated from it by treating it with a diluted acid. The leuco body remains as a white or reddish crystalline powder. It is slightly soluble in water, readily soluble in alcohol and acetone. In diluted caustic soda lye it dissolves with a yellowish color and this solution, when exposed to the-air, yields ared dyestufl.

Example 11: A hot solution of 18 parts by weight of methoxydioxindole in about 4000 parts of water, obtained for instance by reducing methoxyisatin by means of zinc in an acid solution, is mixed with 15 parts of methoXy-alplia-oxythionaphthene, or with 20 parts of an alkyloXy-alpha-oxythionaphthene-betacarboxylie acid and rendered alkaline by means of carbonate of soda. The leuco body thus formed is isolated in the same manner as in Example I. It has "properties similar to those described above; from its alkaline solution there separates, on exposure to the air, a dyeslull varying in color from orangeyellow to brown.

Having now described our invention, what we claim is:

l. The process for manufacturing leuco bodies containing sulfur by condensing dioxi doles with alpha-oxythioua ihlheues.

2. As a new product,a leuco body coutain indole with an alpha:oxythionaphthene, be- In testimony whereof, we afi'ix our signaing a white or reddish crystalline powder tures in presence of two witnesses.

which is slightly soluble in Water, soluble in BENNO HOMOLKA.

alcohol .and acetone 'and also in diluted ROBERT \VELDE.

5 caustic alkalies, its solution'in caustic alka- \Vitnesses:

lies separating, oil-exposure to the air, an JEAN GRUND,

insoluble dyestufi. CARL GRUND. 

